Detergent composition



Patent e 6 May 11', 1937 PATENT OFFICE DETERGENT COMPOSITION TheodoreIt. Donlan, Irvington, N. J., assignor to Stanco Inco p rated NoDrawing. Application Mayuspiags,

Serial No. 671,002

3 Claims. 1 (Cl. 875) This invention relates to improved detergents andmethods of making and using same, and it relates more particularly to acleaning fluid for removing oily and greasy films'from glass or metal.

Broadly, the invention consists in adding to water a major percentage ofa water-soluble organic solvent adapted to lower the surface tension ofthe water and to aid in cleaning, and a minor percentage of a wettingagent; especially.

an oil-soluble one. As the water-soluble organic solvent, isopropylalcohol is particularly well suited and it may be used in percentagesvaryin over a fairly wide range such as from 20 to 50%, even '10 to 80%or so. Isopropyl alcohol evaporates slower than ethyl alcohol butfasterthan normal propyl alcohol and faster than tertiary butyl alcohol, 1.e.-, it evaporates not too fast and not too slow. However, if isopropylalcohol is not available, other. low molecular weight alcohols may beused, or other types of solvents such as acetone and the like. thissolvent is to lower the surface tension and to clean. By lowering thesurface tension, several advantages are attained; one is aiding thespreading and another is hastening evaporation. The addition of30% ofisopropyl alcohol to distilled water lowers the surface tension from70.6 dynes per sq. cm. to 29.5 at 31 C.

As wetting agent, it is preferred to use a small amount of a soapproduced by neutralizing the oil-soluble sulfonic-acids produced by thetreatment of liquid petroleum fractions with strong sulfuric acid. Suchoil-soluble sulfonates may be produced and purified according to any ofthe known methods. Although the properties -of the oil-solublesulfonates may vary according to the source of the crude from which theyare produced and also according to the gravity, viscosity or boilingpoint of the fraction treated, any of these sulfonates may be usedaccording to the invention providing they have a suitable wetting power.By this is meant that when a small percentage, for example 0.1% ofoil-soluble sulfonate soap is added to an aqueous alcohol solution,

it greatly facilitates the spreading of the solution over an oily andgreasy surface. This wetting or spreading ability is readily observed bycomparing an aqueous alcohol solution alone and one The primary functionof containing a small percentage of the sulfonate. This sulfonateenables the solution to flow quickly and evenly over the surface andthereby reduces the amount of rubbing required and gives a quickercleaning and polishing. The spread- 5 ing of the solution into a thinfilm over the en- 'tire surface to be cleaned also causes a quickerevaporation of the solution, thereby reducing the length of timerequired to produce a cleaned and polished surface. This'sulfonate soaplowers the 10 surface tension of the aqueous alcohol solution and keepsthe surface tension down even when V the alcohol evaporates.

Generally it is desirable to use only so much of this oil-solublesulfonate as will actually dissolve 15' face being cleaned. It may bedifllcult to remove 25 such a. fog.

Other types ,of soaps may be used although not with the same degree ofsuccess as the oilsoluble sulfonates just described,'for example, thecommercial soaps prepared by the saponification of caustic soda andanimal or vegetable fatty oils and water-soluble sulfonates derived frompetroleum. Generally, however, these soaps do not spread as evenly andquicklyas the preferred oil-soluble sulfonates. The water-solublesulfonates can be made to spread by' the use of larger amounts of it,but when this happens a fog is apt to be produced on the surface beingcleaned,

which is difllcult to remove. If desired, a mixture of these soaps maybe used such as a small amount of the oil-soluble sulfonate along withone of the other types of soap.

A small amount of dye, perfume, and other such minor ingredients may beadded to the composition if desired.

The improved detergent has been found particularly useful in cleaningautomobile Windshields and other glass surfaces which have become coatedwith a slight oily or greasy film which is difilcult to remove withwater alone and which it is undesirable to clean with water containing alarge amount of soap. As a specific example of suitable composition forcleaning automobile This solution is applied to the glass preferably byspraying, or also by a cloth, or in any other suitable manner, isquickly distributed over the en tire surface and then polished with aclean, dry cloth or wiped off clean with a squeegee (rubber scrapingblade). Various other types of windows, etc. or metal surfaces, orenameled metal surfaces, may be cleaned in a similar manner.

The oil-soluble sulfonate used in the above example was obtained as abyproduct from the manufacture of mineral white oil. The sulfonateproduct, however, was purified by the method which comprises isolatingthe oil-soluble sulfonates directly from the alcoholic aqueous solutionby agitating with alkali carbonates, drawing ofi and filtering the upperlayer and evaporating the filtrate to dryness. Although in themanufacture of a commercial mineral white oil a wide variety of crudeoil stocks may be used and the amount and concentration of the acid usedfor treating may be varied according to the stock being treated, theoil-soluble sulfonate from any such treatment is generally satisfactory.Usually, it is desirable to use sulfonates having a molecular weightbetween the approximate limits of 350 and 700 although this is not adefinite requirement as some products have been found satisfactory bothabove and below those limits. It is also possible to make a highermolecular weight sulfonate compound suitable for use by admixingtherewith some other sulfonate product such as a lower molecular weightoil-soluble sulfonate.

For the purposes of ease in commercial handling, storage, etc. a stocksolution of the detergent may be produced by dissolving a suitablepercentage (from 0.2 to 5%) of oil-soluble sulfonate in isopropylalcohol. This stock solution will, when diluted with water, be ready touse.

It is not intended that the invention be limited by any of the specificexamples given merely for the sake of illustration or by any of thetheories of the operation of the invention but in the appending claimsit is intended to claim broadly all inherent novelty in the invention.

I claim:

1. A non-corrosive detergent composition comprising about 20-50% ofisopropyl alcohol, about 0.1% of an oil-soluble sulfonate derived frompetroleum oil and about 50-80% of water, with such small amounts ofminor ingredients as dyes, perfumes, and the like as may be desired.

2. A stock solution adapted to be diluted with water and used fordetergent purposes comprising chiefly isopropyl alcohol with from about0.2 to 5% of an oil-soluble sulfonate derived from petroleum oil.

3. The method of cleaning automobile windshields and similar surfaceswhich comprises rubbing over said surfaces a non-corrosive detergentsolution comprising about 20-50% of isopropyl alcohol, about 0.1%v of anoil-soluble sulfonate derived from petroleum oiland about 50-80% ofwater, and thereafter wiping the surface dry.

THEODORE R. DONLAN.

